tweddell



(No Model.) 9 v R. H. TWEDDELL, J. PLATT 82: J. FIELDING.

RIVETING MACHINE.

Patented Jan. 6, 1885.

; mam/1005a RALPH HART TW'EDDELL, OF W'ESTMINSTER, COUNTY OF MIDDLESEX,AND

JAMES PLATT AND JOHN FIELDING, OF GLOUCESTER, COUNTY GLOUCESTER, EN GLAND.

RlVETING MACHiNE.

EE'QCIFTCATION forming part of Letters Patent No. 310,51-6, datedJanuary 6, 1885.

Application filed April 19, 1881. (No model Patented in England Februaryfl, 1883, No. 5117; in France August 6, 1883,

No. 156,893, and in Belgium August H. 18:53, No. 62,233,

To all whom it may concern.-

Be it known-that we, RALPH HART Twen- DELL, of 'Westminster, in thecounty of Middlesex, and J AMES PLATT and Joan FIELD- ING,Of Gloucester,in the county of Gloucester and country of England, have inventedcertain new and useful Improvements in Direct- Acting Hydraulic Machinesfor tiveting; and we do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertaius to make and use thesame;

Our invention relates to hydraulic or other fluid-pressure machines,andmore particularly to means for varying the power of direct-act inghydraulic machines for riveting and such like operations, so that theirtools can be applied with more or less force according to the nature ofthe work to be done. For this purpose we provide the hydraulic cylinderof the machine with a differential plunger and with suitable valves, sothat the thud-pressure can be made to act either on the smaller area ofthe plunger, or on its annular area,or on both areas, the force withwhich the plunger carrying the tool is advanced being thus capableofthree variations.

-In the accompanying drawings, Figure 1 is a view in longitudinalsection of our improved riveter. Fig. 2 is an end view of the same, andFigs. 3, at, and 5 represent modifications.

Gr represents a differential cylinder, removably secured to the base orframe H, and pro vided with ports communicating with both areas thereof.The plunger A is also made differential, so that the pressure can bemade to act on both the annular area and the circular end area, D. Thehead E of the plunger, which carries the riveting-tool,is madeeccentric, so that when the cylinder G is unscrewed from its place andthe small or draw-back cylinder F removed, the plunger and head can belowered sufficiently far to allow the head E to pass under the upperpart, H,of the frame. By this construction we are enabled to make theplunger and head in one piece. The plungel A is suitably packed withinthe cylinder 'lat-or. (Not shown in the drawings.)

G, and is operated by water or other fluid admitted into the cylinderunder-high pressure.

The valve 0, which is preferably a screwvalve, is adapted to close theport ai'rom communicating with the port I), which latter directs thewater against the annular area B of the plunger. lowing the water toenter the port 0 it passes from thence into the cylinder and actsagainst the annular area of the plunger, forcing the latter out. If itis desired to increase the pressure, it is simply necessary to open thevalve 0 and admit the water to the circular area 1) simultaneously withits admission to the. annular area B. The inner end of the plunger isconsider-ab] y enlarged, and formed eccentrically to the main portionthereof, thereby forming a shoulder or abutment, (1, against which oneend of the small push-back plunger A. bears. The cylinder F isremovable, and is provided with asuitable pipeconnection to the pressurereservoir or accumu This cylinder opens toward the shoulder d of thepluir ger A, and is provided with a plunger, the outer end of which isadapted to bear against the plunger A. After the pressure on the plungerA has been relieved by opening the exhaust,the pressure in cylinder Fforces the rain out and pushes plunger A back within its cylinder.

Fig. 3 shows a modified arrangement of ports for admitting theworking-fluid into the cylinder. In this construction the water, insteadof being admitted into the side of the cylinder, is admitted at the endbetween the ports a and b. Each of these ports is provided with ascrew-valve for shutting off the supply from either area of the piston.

A cylinder and plunger representing variable area maybe constructed asshown in Fig. 4, the drawback being effected by a rod, 1'. In thisinstance the large cylinder G is provided centrally with the smallercylinder, G, both cylinders being provided with suitable supply-ports.The plunger A consists, essentially, of a large plunger, G fitting inthe larger cylinder and surrounding the smaller Thus it will be seenthat by alcylinder, G, and the smaller plunger, G, Having fullydescribed our invention, what working in the smaller eylinder,G, bothplun- I we claim as new, and desire to secure by Let gcrs being rigidlyconnected at their outer ends.

WVhen it is desired to operate the riveter, water is admitted to eitheror both cylinders G G, and the pressure correspondingly increased asdesired. It is of advantage to .lllitke a communication between one ofthe cylinders and a low-pressure cistern bya pipe, K, and interpose acheek-valve, K, for the purpose of preventing the water in said cylinderfrom flowing back into the low-pressure cistern. In the drawings we haveshown the pipe and check-valve applied to the larger cylinder. Now, byadmitting water to the smaller cylinder the differential plunger isforced outwardly and a vacuum is formed in the larger cylinder. Thiscauses the checkvalve K to rise and water from the low-pressure cisternto flow into the larger cylinder. If the smaller cylinder alone isinsufficient in power to perform the work, pressure-water is thenadmitted into the larger cylinder,and as the latter has been filled withwaste water no loss of high-pressure water is occasioned.

Fig. 5 is a sectional view showing another construction of differentialcylinder, the cylinder in this case being the moving part, While theplunger is stationary. In this i11- stance the ram or head E is providedat its rear end with a circular cavity forming the main cylinder,inwhich the stationary plunger E rests. This plunger is provided with aport, Z), adapted to be closed by a screw-valve, and is also providedcentrally with a cylinder in which the plunger a of the ram E moves.This cylinder is also provided with a port, a adapted to be closed by ascrew-valve. Thus it will be seen that the water can be admitted to theannular area B, or to the circular area D, or to both, as desired. Thedraw-back mechanism is similar to that shown in Fig. 1.

\Ve are aware that a differential cylinder and plunger have beenemployed in hydraulic presses,and that adrawback plunger has beenemployed in riveting-machines, and hence we do not claim them, broadly;but,

ters Patent, is

1. In a riveting-machine, the combination, with a differential cylinderand plunger, of a push-back plunger arranged in direct contact with theforward portion of the differential plunger, and adapted to force itthrough its back-stroke, substantially as set forth.

2. In a riveting-machine, the combination, with a base, a large cylinderremovably secured thereto, and a riveting-plunger the inner end of whichis enlarged, of the removable cylinder F and the push-back plunger, oneend of which bears against the enlarged end of the riveting-plunger.

The combination,with a base, a remova- 6 ble cylinder secured thereto,and the differential plunger provided with anenlarged inner end, andwith a head for holding the rivetingtool, arranged eccentrically to thebody thereof, of a removable cylinder, F, and a small plunger working insaid cylinder and bearing at one end against a shoulder of thedifferential plunger.

4. In a riveting-machine, the combination, with a frame and adifferential cylinder re movably secured to the frame, of a differentialplungenthe removable cylinder F, and

the push-back plunger, all of the above parts adapted to operate asdescribed. In testimony whereof I have signed this Specification in thepresence of two snbscrib ing witnesses.

RALPH HART TWEDDELL.

Witnesses:

H. G. Soo'r'r, XVM. BAILEY.

In testimonywhereof we have signed this specification in the presence oftwo subscribing witnesses.

JAMES PLATT. JOHN FIELDING. \Vitnesses:

JOHN A. Porn, H. CADENNE.

